<!DOCTYPE html>
<html lang="zh-CN">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<style>
    /* 
        同font属性一样，可以简写
    */
    div {
        width: 600px;
        height: 600px;
        background: #000 url(./../resources/素材2.png) no-repeat center bottom/cover;
    }
</style>

<body>
    <div>背景图</div>
</body>

</html>